Track drive machines typically include those with metal or composite cleats that are connected together to form continuous loops and those constructed of reinforced polymer/rubber materials that are manufactured in endless loops.
Tracked vehicles are typically designed so as to produce ground pressures lower than that of wheeled vehicles. Heavy machines are typically below 15 lb/in2, but lightweight machines are ranging as low as 1 to 3 lb/in2. The stiffness of the track is selected to minimize flexing between the bogie wheels. The track is therefore kept substantially straight between the bogie wheels, idlers, and the drive sprocket to increase the efficiency associated with transference of power to the tracks and losses due to misalignment. Track tension, especially for non-metallic endless-loop configurations, must be maintained within prescribed parameters in order to prevent buckling in slack sections.
Drive sprockets are sometimes positioned above the ground to reduce contamination, reduce complexity in the design while effectively transmitting power to the tracks. Positioning the drive sprockets above ground also helps to prevent derailing of the track. Tracks are generally held in a constant state of tension on the drive sprocket and the roller, and this also helps to prevent derailment.
These offerings have limitations in performance in regard to lateral derailment of tracks, drive lug skipping (ratcheting), and backlash impacts from sprocket engagement to drive lug during traction direction load reversals.
A need therefore exists for a drive sprocket for a tracked vehicle in which the drive sprocket maintains closer engagement with guide lugs on track. A need also exists for a drive sprocket for a tracked vehicle that reduces the wear and increases the longevity of the guide lugs and adjacent lugs on the track.